Summary: This project seeks to develop new genetic tools to aid in research into the genetic bases of virulence in Bacillus anthracis. Tools which are required for state of the art genetic analysis would include: transposon mutagenesis, allelic exchange, interspecies (E. coli to B. anthracis) conjugation, genetic (recombinational) mapping, etc. Although some of these tools have been reported in the literature, subsequent attempts to use them have met with variable success. Initially, we plan to evaluate genetic tools currently available by testing in the model systems used by other CBER researchers investigating Anthrax. Subsequently we would plan to develop new tools where possible to facilitate and enable more advanced genetic analyses in this important pathogen.